Filter devices of the aforementioned type are state of the art and are used in a variety of fields. A few examples that can be mentioned from the vast number of possible applications include the applications for water treatment, potable water filtration, the production of pure water and ultrapure water, the filtration of cooling lubricants and washing fluids, etc. With respect to the state of the art, reference is made to the line filter marketed by Hydac Process Technology GmbH of Neunkirchen, Germany, under the product name PLF1 and embodies a filter device of the type described in the foregoing.
When such line filters are to be used for applications in which a fine filtration of large volumetric flow rates is necessary and a correspondingly large filter surface area, for example, exceeding 500 m2, has to be provided, problems arise both with respect to the design of the filter housing and with respect to carrying out the replacement procedures for replacing the used filter elements. In the case of filter surface areas exceeding 500 m2 using filter elements in the form of conventional filter cartridges having a diameter of 67 mm and a length of 40 inches, dimensions that correspond to a filter surface area of about 1 m2, the filter housing must provide more than 500 element holders as installation slots for the filter elements. The result is housing dimensions that are difficult to service, in particular, with respect to replacing the elements. Therefore, the state of the art provides such filter surface areas only by a plurality of filter housings.